1. Field of the Invention
The present invention relates to root canal therapy and, more particularly, but not by way of limitation to a method and apparatus for filling a root canal of a tooth.
2. Description of the Related Art
Root canal therapy is a well-known dental procedure. The procedure includes removing a top portion of a diseased tooth, cleaning the tooth's root canals and pulp portion, filling the extirpated root canals with a rubbery compound, such as gutta percha, and cementing a crown to the tooth.
The root canal of the tooth extends from the pulp chamber to a tip, which is known as the apical foramen, of the tooth's root. In addition, the walls of the root canal form fissures and voids. It is desired to fill these fissures and voids as well as the main root canal during the filling process.
One method of filling the extirpated root canal utilizes a solid cone of gutta percha, which is known as the master cone. The master cone is placed within the root canal. Smaller cones, called accessory cones, are positioned around the master cone completing the filling of the root canal.
Another method of filling the root canal utilizes warmed gutta percha. This warmed gutta percha is injected into an extirpated root canal and allowed to cool completing the filling of the canal.
However, these methods suffer several disadvantages, namely overfilling and underfilling the root canal. An overfill occurs by positioning the master cone of gutta percha or injecting warmed gutta percha past the apical foramen into the surrounding bone and tissue. This positioning of the gutta percha may irritate the bone and periodontal ligament surrounding the tooth.
An underfill occurs with a gutta percha cone by failing to get the cone tip to the apical foramen of the tooth. Using warm gutta percha may also result in underfilling the root canal. Warmed gutta percha flows well in large cavities, but not in small cavities, such as the cavity near the root's apical foramen and the fissures and voids extending from the canal. As a result, using warmed gutta percha requires gutting of the tooth to enlarge the root canal for increasing the flowability of the gutta percha. The gutting of the tooth weakens the root potentially leading to future root fractures.
In addition to the problems of overfill and underfill, both procedures extend the procedure time for filling the root canal.
Accordingly, a method for filling root canals that eliminates overfill and underfill and decreases the procedure time will improve over conventional root canal fill methods.